The speed of an object may be measured using a radar based measurement device. The radar based measurement device bounces a radio signal off a moving object and measures the frequency shift to calculate the speed of the object.
Radar based measurement devices are useful for all sorts of speed measurements including object velocity measurements for sports or vehicle speed measurements for law enforcement purposes. Radar based measurement devices are highly useful.
Radar based measurement devices are highly specific equipment, however, typically able to only perform one function. Unless one knows they will be performing a speed measurement at a particular place or time, it is unlikely a radar based measurement device will be on hand.
In some cases it would be useful to be able to perform unplanned speed measurements. This could be at a baseball game or tennis match. In these situations it would be useful to have a way to perform speed measurements using a device that it typically available or that is normally carried.
Certain applications (“apps”) for mobile smart phones for measuring the speed of thrown pitch exist. These applications require you touch a ‘button’ at the start of the pitch and then release the button when the pitch is caught by the catcher. The speed of the pitch is estimated based on the time during which the button was depressed. Depressing a button on a touch screen is a highly inaccurate process, however. Errors of even a 0.1 of a second are very common. As such, the speed estimate made by these applications are highly inaccurate.
Additionally, there are other smart phone applications that allow video to be taken and the video to be reviewed in slow motion or in single frame steps. Such apps are helpful for observing object and people moving at relative higher speeds. However, these slow motion apps are not configured to allow for measurement of the speed of a thrown object.